The currently available winged needle sets and prior art, particularly those using relatively large diameter needles typically larger than about 17 gauge, have “wings” that are believed to be at least 34 mm. wide on arteriovenous fistula sets. This is true when the tubing of said sets is large, typically with an outer diameter of at least about 5.0 mm., and when small tubing on scalp vein sets has only an outer diameter of 2 mm. or less.
It is now mandated by law that many needle sets must carry a needle protector to protect handlers of the set from accidental needle stick, after the needle has been used and withdrawn from the patient. An example of such a device is the MasterGuard® Slotted Needle Guard sold by Medisystems Corporation of Seattle, Wash., in which the needle guard passes along the wings of the needle to be protected, with the wings projecting outwardly through the slots.
Various slotless tubular needle guards are known as well, one such guard being proposed for use with a winged needle, namely the WingEater needle guard of JMS Co., Ltd., as illustrated in PCT published application WO 02/30491 A1 (in Japanese). A problem with this design resides in the difficulty in getting the wings to fold properly as a wide mouthed tube is advanced to enclose the winged needle by the tubular needle guard. Furthermore, the WingEater needle guard has a small pocket at the bottom of the front end thereof for capturing the point of the needle. In the practice of hemodialysis, the needle is often “flipped” by 180° rotation after insertion into the vein, in an attempt to maximize blood flow through the needle. In the flipped position, it is difficult or impossible for the needle tip, when removed from the patient, to be captured by the forward pocket of the WingEater device.
In accordance with this invention, a realization has arisen that there is no real need, especially in the case of larger winged needle sets where the needles are essentially no smaller than about 17 gauge, for the wings to be as wide as 34 mm. or more. Such hubs are large enough to be more readily graspable on their own than hubs of smaller needles. It may be that aesthetics has been a chief driving force for the design, but, in fact, it has been determined in accordance with this invention that a substantially narrower wing is useable, even with the larger diameter needles utilized in hemodialysis, blood collection, and the like. With a narrower wing, it becomes possible to develop a tubular, open-ended needle guard which can receive a winged needle without any need to fold the wings. Such a needle guard may have the advantage of easy needle insertion, plus a sealing capability against spillage of blood from the tubular needle set which carries the guard while the needle is guarded. By this invention, a set can be completely sealed after use. Also, the set can be safely and effectively sealed whether the winged needle is in the normal or the “flipped” position.